Tilting suspension for crawler frames



Dec. 28, 1965 G. N. LA CASSE 3,225,349

TILTING SUSPENSION FOR CRAWLER FRAMES Filed Feb. 21, 1964 2.Sheets-Sheet 1 Fig.2.

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24 INVENTOR 3O 34 36 32 GEORGENLACASSE his ATTORNEY Dec. 28, 1965 G. N.LA CA SSE 3,225,849

TILTING SUSPENSION FOR CRAWLER FRAMES Filed Feb. 21, 1964 2 Sheets-Sheetz m w M" 34 A Im- 24 Fig.5.

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l 74 48 o GEORGENLACASSE 7 BY Q cb Q) 03 XMKM his ATTORNEY United StatesPatent Oil Free 3,225,843 Patented Dec. 28, 1365 3,225,849 TILTINGSUSPENSIGN FOR ERAWLER FRAMES George Norman La Casse, Claremont, N.H.,assignor to Joy Manufacturing Company, Pittsburgh, Pan, 3 corporation ofPennsylvania Filed Feb. 21, 1964, Ser. No. 346,500 3 Claims. (Cl.ISO-9.5)

This invention relates to a drilling device and more particularly to acrawler mounted mobile drill carriage having a novel frame suspensionwhich provides for relative tilting movement of the crawlers withrespect to each other when traveling over an irregular surface.

The drilling device of the present invention contemplates the use of asimilar crossbar for supporting the drill support frame, which crossbar,by the use of spherical bearings eliminates the need for universallymounted links. The novel structure of this invention is stronger andmore rigid than that of the prior art structures and can be constructedmore economically since fewer pieces of material are necessary in theconstruction of the device of the present invention resulting in economyin manufacture and assembly.

It is-therefore an object of this invention to provide a new andimproved mobile drill carriage.

It is another object of this invention to provide a new and improveddrill carriage for travelling over an irregular surface.

It is a further object of this invention to provide a new and improveddrill carriage having a drill support frame supported by a crossbar,which crossbar is connected to a pair of crawler frames by simple balljoint connections.

It is still another object of this invention to provide a new andimproved crawler mounted drill carriage having a novel frame suspensionwhich provides for relative tilting movement of the crawlers withrespect to each other when travelling over an irregular surface, whichframe suspension comprises a minimum of moving parts.

These and other objects and advantages of this invention will more fullyappear upon consideration of the following description and drawings inwhich:

FIGURE 1 is a side elevational view of a mobile drill mounted on a drillcarriage constructed according to the principles of this invention;

FIGURE 2 is an enlarged, fragmentary, sectional view taken substantiallyon the line 22 of FIGURE 3;

FIGURE 3 is a top plan view of the mobile drill carriage shown in FIGURE1;

FIGURE 4 is a sectional view taken on the line 44 of FIGURE 3; and

FIGURE 5 is a front elevational view of the mobile drill carriage shownin FIGURE 3.

Referring now to the drawings, there is shown in FIG- URE 1 a drillingdevice comprising an elongated drill frame 12 having mounted thereon andfeedable therealong a drill motor 14 provided with an elongated drillrod and drill bit 16 for producing bores in rock strata in a manner wellknown in the art. The drill frame 12 is pivotably and longitudinallyadjustably mounted on a suitable drill support boom 18 pivotablyadjustably mounted on a support member 20 which is in turn mounted onand supported by a main frame 22 (see FIGURES 3 and 4) hereinafter morefully described.

Two crawler mechanisms 24 and 26 of a well known type are held inlaterally spaced parallelism by the main frame 22 and associated membersas hereinafter more fully set forth. The crawlers 24 and 26 are suitablypowered by suitable motors 28 suitably connected through control meansto a device providing energy such as electrical current or compressedair for operation of the crawlers 24 and 26 in a well known manner.

Each of the crawlers 24 and 26 comprises an endless chain 30 trainedabout and driven by a drive sprocket 32 powered by one of the motors 28and rotatable about a common centerline A-A (see FIG. 3) by suitablespeed reduction gearing interposed between the motor 28 and therespective sprocket 32. An idler sprocket 34 (see FIG. 1) as well as thedrive sprocket 32 is mounted on a crawler frame 36 for each of thecrawlers 24 and 26 with each of the crawler frames 36 being providedwith suitable guides and rollers for control of the orbiting of thechain 30 thereabout. For purposes of explanation the end of the machineshown to the left in FIGURES 1 and 4 will be hereinafter referred to asthe forward end and the longitudianl dimension of the machine will bethat taken along the line 4-4 of FIGURE 3 with the idler sprocket 34 atthe forward end of the caterpillar 24 and the drive sprocket 32 at therearward end of the crawler 24.

The main frame 22 comprises an elongated heavy walled steel tube ofrectangular cross section extending transversely across the drillingdevice 10 and located forwardly and upwardly from the axis AA of thedrive sprockets 32. The ends of the tube 49 are rigidly secured to apair of rearwardly extending bracket plates 42 pivotably mounted on thecrawler frames 36 respectively for limited rotation about the axis AAwith the motors 28 suitably mounted thereon and located rearwardly ofthe axis AA. From an intermediate portion of the tube 40 a centralbracket 44 extends rearwardly and downwardly a suflicient distance toencompass a bore 46 coaxial with the axis A-A. An elongated cylindricalpin 4-8 is rigidly secured in the bore 46 and pivotably received in ajournal end 50 of a support beam 52 which extends forwardly andtransversely from the central bracket 44 to an intermediate portion ofthe crawler frame 36 of the righthand crawler 24. In like manner alefthand support beam 54 having a journal end 56 pivotably receiving anend portion of the pin 48 extends obliquely forwardly from the centralbracket 44 to a central portion of the crawler frame 36 of the lefthandcrawler 26.

Extending transversely of the machine from an intermediate portion ofthe support beam 52 to an intermediate portion of the support beam 54 isan elongated crossbar member 53 having an axis parallel to the axis A-Aand in a common horizontal plane therewith (see FIG. 3).

The crossbar member 56 as shown comprises an elongated main portion ofrectangular cross section with a stepped cylindrical element 58 rigidlysecured in each end thereof and extending longitudinally outwardlytherefrom with the two end elements 58 being coaxial with each other andwith the main portion of the crossbar 56 (see FIG. 2). A reduceddiameter portion 59 of the cylindrical element 58 at each end of thecrossbar 56 is fitted to the inner diameter of a spherical bearing 60 ofa type well known in the art and characterized as a selfaligningtwo-piece bearing having a partially spherical inner element 61 mountedin a cylindrical outer element 62 having a partially spherical innersurface mating with the outer surface of the inner element 61 so thatthe inner element 61 is universally pivotable within a limited range ofangles within the outer element 62. The inner element 61 is secured onthe reduced diameter portion 59 in any suitable manner as by a washer 64and a nut 65 as shown. The outer element 62 is slidably mounted in anaxial bore 66 of a generally cylindrical bearing bracket 68 providedwith an integral oblique base 79 rigidly removably secured to anintermediate portion of one of the beams 54 or 52. Thus the crossbar 56is universally pivotably connected between the intermediate sections ofthe beams 52 and 54 with the slidable relationship of the outer element62 to the bore 66 providing for a change in length made necessarywhenever the crawler 24 rotates about the axis A-A in relation to thecrawler 26, which rotation takes place to a greater or less degreealmost continually as the device It traverses irregular ground or othersupporting surfaces.

A transverse bore 73 through the center of the crossbar 56 slidablyreceives an elongated cylindrical pin 72 having an axis coinciding withthe centerline of the machine (line 44) in the horizontal planecontaining the axis A-A when the machine is standing on a fiat, levelsurface. The pin 72 is rigidly secured to the lower end of a bracketplate 74 rigidly secured to and down- Wardly depending from the lowerfront central portion of the tube 40. The bracket plate 74 and the pin72 provide a third support point, in conjunction with the brackets 4-2,for the main frame 22 so that the frame 22 is rigidly supported on athree point suspension while the crawlers 24 and 26 are free to rotatewith respect to each other about the axis AA within limits imposed bythe structural clearance between the frame 22 and the beams 52 and 54.When the drilling device 10 is operating upon an irregular surface thecrawlers 24 and 26 will at times necessarily rotate about axis AA inrelation to each other as for example when the forward end of thecrawler 26 is raised in relation to the position of the forward end ofthe crawler 24 as shown in FIGURE 5 the following actions will takeplace: the end of the crossbar 56, nearest the crawler 26, will risecausing the crossbar to extend obliquely from one bearing bracket 68 tothe other necessitating a lengthening of the connection extendingtherebetween. With a given size of machine this lengthening amounts toapproximately .22" for an angle of 7 /2 as measured between thehorizontal plane and the centerline of the crossbar 56. This amount oflengthing is accomplished by movement of the outer elements 62 withinthe bores 66 a distance of .11" towards the centerline, as measuredwithin each bore 66. While the above described action is takin place thepin '72 has been carried upwardly by an amount equal to one-half therise of the bracket 6d associated with the crawler 26 and consequentlythe forward edge of the main frame 22 has also been carried upwardly byone-half the amount of the rise of the aforementioned bracket 63. Thusit is seen that the crawlers 24 and 26 are free to rotate about the axisAA with respect to each other but that rigid three point support of themain frame 22 remains in effect although a slight tipping of the mainframe 22 does take place. It is to be realized that as the main frame 22rotates about the axis AA there is a slight change in the distance fromthe axis A--A to the center of cross bar 56 which change in distance isaccommodated by the sliding fit of the pin 72 in the transverse bore ofthe crossbar 56 allowing the necessary variation in length to take placewithout interfering with the rigidity of the assembly.

The structure of the present invention is very rigid in that thecrossbar is not free to move forwardly and backwardly relative to thecrawler frames but is only free to rotate about a fixed centerline sinceboth ends of the crossbar although pivotable with relation to thesupport members and free to move transversely of the machine, cannotmove forwardly or rearwardly with respect to the support members. Thestructure of the present invention employs only two relative largespherical bearings having an outside diameter of approximately twoinches.

It is to be realized that although the crossbar has been described asbeing mounted in spherical self-aligning bearings, other types of balland socket joints having the required degree of angular and longitudinalfreedom with respect to the crossbar 56 can be employed in place of thespherical bearings 60.

It is to be realized that a preferred embodiment of this inventionhaving been described, other embodiments of these principles arepossible and envisioned as being within the scope of this invention. Itis therefore respectfully requested that this invention be interpretedas broadly as possible and be limited only by the prior art.

I claim:

l. A mobile rock drill support comprising: two parallel crawlerassemblies having a crawler frame within each of said assemblies;rearward portions of said assemblies having a common transverse axis,said assemblies being pivotable about said axis; a transverse framepivotable about said axis and pivotably secured to said crawler frames;two elongated rigid support members, rigidly secured to and extendingrearwardly and 1nwardly from intermediate portions of said crawlerframes, respectively, said support members being pivotably secured toeach other along said axis; spherical bearings transversely slidablymounted on intermediate portions of said support members, respectively;an elongated rigid crossbar member extending between and universallypivotably secured by said spherical bearings; said crossbar memberhaving a central transverse bore therethrough and being pivotablyconnected to said transverse frame through said bore, said bore havingan axis normal to said transverse axis and said crossbar member beingslidable along the axis of said bore to permit said crawler frames torotate with respect to each other within the limits imposed by theclearance between said rigid frame and said support members.

2. A mobile rock drill support comprising: two parallel crawlerassemblies; a crawler frame within each of said assemblies; rearwardportions of said assemblies having a common transverse axis, saidassemblies being pivotable about said axis; a transverse frame pivotableabout said axis, pivotably secured to said crawler frames; two elongatedrigid support members, rigidly secured to and extending rearwardly andinwardly from intermediate portions of said crawler frames,respectively, said support members being pivotably secured to eachother; spherical bearings mounted on intermediate portions of saidsupport members, respectively, said bearings being slidable transverselyof said support members; an elongated rigid crossbar member extendingbetween and universally pivotably secured to said spherical bearings;said crossbar member having a central transverse bore therethrogh; pivotmeans rigidly secured to said transverse frame, said bore and said pivotmeans having a common axis normal to said transverse axis and said boreslidably receiving said pivot means to permit said crawler frames torotate with respect to each other within the limits imposed by theclearance between said rigid frame and said support members.

3. A mobile rock drill support comprising: two parallel crawlerassemblies; a crawler frame within each of said assemblies; rearwardportions of said assemblies having a common transverse axis, saidassemblies being pivotable about said axis; a transverse frame pivotableabout said axis, pivotably secured to said crawler frames; two elongatedrigid support members, rigidly secured to and extending rearwardly andinwardly from inter mediate portions of said crawler frames,respectively, said support members being pivotably secured to eachother; universally pivotable bearings mounted on intermediate portionsof said support members, respectively, said bearings being sl-idabletransversely of said support members; an elongated rigid crossbar memberextending between and fixedly secured to said universal bearings; saidcrossbar member having a central transverse bore therethrough; pivotmeans rigidly secured to said transverse frame, said bore and said pivotmeans having a common axis normal to said transverse axis and said boreslidably receiving said pivot means to permit said crawler frames torotate with respect to each other within the limits imposed by theclearance between said rigid frame and said support members.

References (Iitetl by the Examiner FOREIGN PATENTS 5/1920 Germany.

BENJAMIN I-IERSH, Primary Examiner.

ARTHUR L. LA POINT, Examiner.

3. A MOBILE ROCK DRILL SUPPORT COMPRISING: TWO PARALLEL CRAWLERASSEMBLIES; A CRAWLER FRAME WITHIN EACH OF SAID ASSEMBLIES; REARWARDPORTIONS OF SAID ASSEMBLIES HAVING A COMMON TRANSVERSE AXIS, SAIDASSEMBLIES BEING PIVOTABLE ABOUT SAID AXIS; A TRANSVERSE FRAME PIVOTABLEABOUT SAID AXIS, PIVOTABLY SECURED TO SAID CRAWLER FRAMES; TWO ELONGATEDRIGID SUPPORT MEMBERS, RIGIDLY SECURED TO AND EXTENDING REARWARDLY ANDINWARDLY FROM INTERMEDIATE PORTIONS OF SAID CRAWLER FRAMES,RESPECTIVELY, SAID SUPPORT MEMBERS BEING PIVOTABLY SECURED TO EACHOTHER; UNIVERSALLY PIVOTABLE BEARINGS MOUNTED ON INTERMEDIATE PORTIONSOF SAID SUPPORT MEMBERS, RESPECTIVELY, SAID BEARINGS BEING SLIDABLYTRANSVERSELY OF SAID SUPPORT MEMBERS; AN ELONGATED RIGID CROSSBAR MEMBEREXTENDING BETWEEN AND FIXEDLY SECURED TO SAID UNIVERSAL BEARINGS; SAIDCROSSBAR MEMBER HAVING A CENTRAL TRANSVERSE BORE THERETHROUGH; PIVOTMEANS RIGIDLY SECURED TO SAID TRANSVERSE FRAME, SAID BORE AND SAID PIVOTMEANS HAVING A COMMON AXIS NORMAL TO SAID TRANSVERSE AXIS AND SAID BORESLIDABLY RECEIVING SAID PIVOT MEANS TO PERMIT SAID CRAWLER FRAMES TOROTATE WITH RESPECT TO EACH OTHER WITHIN THE LIMITS IMPOSED BY THECLEARANCE BETWEEN SAID RIDIG FRAME AND SAID SUPPORT MEMBERS.